A system of the type referred to above is described, for example, in German OS 2,455,551. It is noted that it is important in the operation of such system that only a relatively small quantity of waste water, e.g. 8 to 40 liters, and, thereafter, a specific quantity of air, be admitted to the vacuum conduit through the check valve, the latter opening only briefly. Thus, the collection chamber or receptacle forming the collector upstream of the check valve is correspondingly small.
Such prior art waste water removal systems have the drawback that, in normal use, the suction of air through the gravity feed lines subsequent to the waste water causes a loud, rather disturbing noise each time the check valve is opened. Moreover, there is the risk that if there is a blockage or other disturbance in the vacuum system or at the check valve, the waste water left over after the filling of the collector receptacle will remain in the gravity feed line and the water level therein will rise until water spills out from an overflow opening in the building.